Limestone Powder Content Research Articles

Fresh and hardened properties of self consolidating Portland limestone cement mortars: Effect of high volume limestone powder replaced by cement

The main purpose of this experimental study is to elucidate the performance of self-compacting mortars (SCMs) composed of high volume limestone powder (LSP). In accordance with this purpose, four different SCMs at which limestone content varied as 0%, 15%, 25% and 35% were designed and later on fresh, hardened and durability properties of the mixtures were investigated for different curing ages depending on the testing method. Compressive strength, splitting tensile strength, rheological properties, mini-slump cone, carbonation, UPV and capillary water absorption were investigated in terms of fresh and hardened performance properties. In term of fresh properties, test results showed that there was a clear increase in the yield stress up to LSP content of 15% and beyond this level there was a tendency of reduction of the yield stress with the increase of limestone addition and also slumps values increased and pointed out a satisfactory fresh property in accordance with the increase in the replacement level of LSP. For mechanical properties, there was a steady decrease in the compressive strength values with the increase in LSP content while the addition of LSP in SCMs more than 15% did not improve splitting tensile strength of the mixtures for all curing ages. As a durability property, carbonation resistance of SCMs samples decreased with the increase in LSP replacement level for all of the mixtures and also UPV values were in an acceptable range of good (for 15%) and doubtful (for 35%) category intervals. Furthermore, the control mixture with the only PC had the lowest sorptivity coefficient as 2.73 cm/s1/2 followed by SCMs with 15%, 25% and 35% LSP as 5.11, 6.13 and 6.14 cm/s1/2, respectively.

The use of limestone to replace physical filler of quartz powder in UHPFRC

One of the key features of ultra-high performance fiber-reinforced concrete (UHPFRC) is the inclusion of quartz powder (QP) as a filler to optimize granular packing. However, QP has not been compared against limestone powder (LP) in terms of the filler effects, although it can affect hydration characteristics, strength development, and autogenous shrinkage of the concrete. In this study, the effectiveness of LP as a filler is evaluated against that of QP in order to verify its potential for use as a functional and human-friendly filler in UHPFRC. For this purpose, five types of fillers consisting of similar-sized QP and LP were designed while maintaining the same water-to-cement (w/c) and superplasticizer-to-cement (sppl/c) ratios. The early age strength increased by up to 12% depending on the LP content, due to the filler effect which accelerates cement hydration by providing a preferential surface for nucleation. Although the 28-day strength was 4%–7% lower than that of the classical UHPFRC containing QP, the 91-day strength was 1%–4% higher. The early age shrinkage was also accelerated by the filler effect of the LP, but its duration was shortened in proportion to the LP content.

Influences of limestone powder on the resistance of concretes to the chloride ion penetration and sulfate attack

Influences of limestone powder on the resistance of concretes to the chloride ion penetration and sulfate attack with a constant water/binder ratio and a constant 28-day compressive strength were studied. The sensitivity of the properties of concrete to the initial moist curing time was also explored. The results indicate that, under a constant water/binder ratio condition, the resistance to sulfate attack of concrete deteriorates with the increasing of limestone powder content, and the resistance to chloride ion penetration decreases when the replacement ratio of limestone powder is 24%. As the initial moist curing time declines, the reducing magnitude of the properties of concrete containing limestone powder is larger than that of plain cement concrete. Nevertheless, lowering the water/binder ratio of concrete containing limestone powder can significantly reduce the sensitivity of the properties of the concrete to the initial moist curing time. No matter how long the initial moist curing time is, replacing cement with 8% limestone powder can improve the resistance of concrete to sulfate attack. Concrete with up to 24% limestone powder addition can still obtain a resistance to chloride ion penetration and sulfate attack similar to plain cement concrete on the premise of a constant 28-day compressive strength. Moreover, it was found that both the crystallization of sodium sulfate and the formation of ettringite collectively result in the deterioration of concrete subjected to the sulfate solution.

Effect of Limestone Powder Content on the Early-Age Properties of CO2-Cured Concrete

AbstractThe effect of limestone powder content on the CO2 curing degree (the carbonation rate after the CO2 curing process), compressive strength, reaction products, and microstructure of concrete ...

Effects of Diatomite–Limestone Powder Ratio on Mechanical and Anti-Deformation Properties of Sustainable Sand Asphalt Composite

Diatomite has gained more and more interest as a new resource, since it has potential as a favorable alternative to mineral filler in the construction of asphalt pavement compared with ordinary limestone powder. In this paper, the mechanical and anti-deformation properties of sand asphalt composites with various proportions of diatomite were investigated by a uniaxial compression failure test, a uniaxial compression repeated creep test, and a low-temperature splitting test in order to determine the optimal replacement content of ordinary limestone powder. Five groups of sand asphalts with various volume ratios of diatomite to limestone (0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25, and 1:0) were determined by the simplex-lattice mixture design (SLD) method. The results reveal that the compression strength, anti-deformation properties, and low-temperature crack resistance of sand asphalts are improved through the use of diatomite. Furthermore, the optimal ratio (0.327:0.673) of limestone to diatomite is determined by the SLD method, according to secant modulus and creep strain results.

Autogenous and drying shrinkage of sodium carbonate activated slag altered by limestone powder incorporation

This paper aims to study the shrinkage mechanism of sodium carbonate activated slag containing limestone powder (LP). The workability, pore structure, reaction kinetics and strength development were characterized. The results show that the autogenous shrinkage increases when the dosage of LP is low (≤30vol%) primarily because of the intensified and accelerated reaction, but decreases when further increasing the LP content due to the dilution effect caused by the reduced binder content. A high amount of limestone powder incorporation slightly increases the pore volume in the range of mesopore and macropore, while its effect on the autogenous shrinkage is not prominent. However, the drying shrinkage of the samples is significantly increased with the increase of LP, caused by the more free water as indicated by the mass loss of the samples. In addition, the decomposition of gaylussite and natron also contributes to the enlarged drying shrinkage.

Use of binary and ternary cementitious blends of F-Class fly-ash and limestone powder to mitigate alkali-silica reaction risk

The aim of this paper was to investigate the effects of binary and ternary cementitious systems including Portland Cement (PC), F-Class fly ash (FA) and limestone powder (LSP) to suppress expansion caused by alkali-silica reaction (ASR). Mortar prisms were prepared with potentially deleterious aggregates and tested by using Mortar-Bar Method according to ASTM C 1260. To evaluate the effect of FA and LSP on the suppression of ASR in mortar, ten different types of mortar were cast with combination of different dosages of FA and LSP as binary and ternary blend systems (partial replacement of PC) while the control mortar consisted of only PC as binder. Moreover, the Scanning Electron Microscopy (SEM) was carried out to interpret the microstructure. It was found that the reduction of ASR expansion rate due to increase in LSP content was more prominent compared to the increase of FA content in the binary blends system. Finally, the mixture containing ternary blends of 20% FA/LSP were in general more effective to mitigate the ASR risk for 14days compared to all mortars.

Effect of limestone powder as a partial replacement of crushed quarry sand on properties of self-compacting repair mortars

Self-compacting repair mortars (SCRM) are particularly desired for the rehabilitation and repair of reinforced concrete structures. The properties of SCRM can be improved by using chemical, mineral, polymer and fiber additives. In limestone quarries, considerable quantities of limestone fine powder are obtained during the process of crushing rock. These fine powders are being collected and their utilization is a big problem from the aspects of disposal, environmental pollution and health hazards. The introduction of limestone powder as cement and sand replacement present interesting possibilities to reduce the cement cost production, CO2 emission and the conservation of natural resources. The effects of limestone powder content in crushed sand on the properties of SCRM are not studied. An experimental study was undertaken to find out the effect of limestone powder content on fresh and hardened properties of SCRM. SCRM mixtures were prepared using crushed sand partially replaced with limestone powder at varying percentages up to 30%. Results indicate that the limestone powder as sand replacement significantly improves the fresh and hardened properties of SCRM with a content ranging from 10 to 15%. The use of limestone powder in repair mortar and concrete application would offer technical, economical and environmental advantages for concrete producers.

Effect of limestone powder as a partial replacement of crushed quarry sand on properties of self-compacting repair mortars

Self-compacting repair mortars (SCRM) are particularly desired for the rehabilitation and repair of reinforced concrete structures. The properties of SCRM can be improved by using chemical, mineral, polymer and fiber additives. In limestone quarries, considerable quantities of limestone fine powder are obtained during the process of crushing rock. These fine powders are being collected and their utilization is a big problem from the aspects of disposal, environmental pollution and health hazards. The introduction of limestone powder as cement and sand replacement present interesting possibilities to reduce the cement cost production, CO2 emission and the conservation of natural resources. The effects of limestone powder content in crushed sand on the properties of SCRM are not studied. An experimental study was undertaken to find out the effect of limestone powder content on fresh and hardened properties of SCRM. SCRM mixtures were prepared using crushed sand partially replaced with limestone powder at varying percentages up to 30%. Results indicate that the limestone powder as sand replacement significantly improves the fresh and hardened properties of SCRM with a content ranging from 10 to 15%. The use of limestone powder in repair mortar and concrete application would offer technical, economical and environmental advantages for concrete producers.

Effect of limestone powder on the rheological, mechanical and durability properties of ECC

This paper presents the results of an investigation on the influence of a replacement of limestone powder (LSP) by silica sand (SS) on properties of engineered cementitious composites (ECC). For this purpose, five different ECC mixtures were adopted: ECC mixture with only SS (M1) for control purposes and four ECC mixtures in which SS is partially replaced by four levels of replacements (25, 50, 75 and 100% by weight of total SS) of LSP. The mechanical properties of ECC were investigated for 3, 28 and 90 days, while the durability tests were performed for 90 days. It was concluded that increase in LSP content resulted in a decrease in fluidity of ECC mixtures indicating longer flow times. Increase in the LSP content had a positive effect on the performance of the compressive strength, fracture toughness and flexural strength at the ages of 3 and 28 days, while this was not valid at the age of 90 days when compared to the reference mixture M1. Moreover, it can be said that the use of LSP instead of SS in ECC mixtures had the positive effect on ductility and good dispersion of fibres due to its fine particle structure compared to SS. On the other hand, the mass loss due to acid attack and the sorptivity coefficient of ECC specimens decreased, while the carbonation resistance increased in all ECC mixes compared to the reference mixture M1 with only SS when LSP content in ECC mixtures increased.

Influence of limestone powder on mechanical, physical and self-healing behavior of Engineered Cementitious Composites

Environmental considerations have led to a global trend of using blended cements instead of ordinary Portland cement; cements containing limestone powder (LP) have recently entered the market. This research focuses on the effect of replacing LP content with cementitious material on the performance of Engineered Cementitious Composite (ECC) containing high-volume fly ash (FA). For this purpose, ECC mixtures were created in which cement and FA were partially replaced by 5%, 10% and 20% of LP and ECC mixture without LP (as control). The samples were precracked at the age of 28days and left under continuous water curing (CW) for recovery of their properties. Compressive strength, modulus of rupture (MOR), mid-span beam deformation capacity, rapid chloride penetration testing (RCPT) and resistivity testing were used to assess the mechanical, physical and self-healing capability of ECC mixtures. Experimental results show that all mixtures exhibited self-healing with slight differences. Microstructure was also assessed using SEM–EDS and XRD analysis. The microstructural analysis of healed cracks in LP-incorporated ECC mixtures showed the presence of calcite, portlandite and C–S–H gels as well as monocarboaluminate, which confirmed a possible reaction between FA and LP. Due to self-healing, the recovery in mechanical and durability performance of the mixtures proposed in this research is anticipated to positively affect life cycle costs and lead to increased civil infrastructure sustainability.

Partially Replacing Fly Ash with Limestone Powder in the Paste - Influence and Characterization

Paste filling is an important research direction of coalmine “green mining” which can dispose coalmines solid waste and achieve environmental protection. The mechanical properties such as compressive strength, workability, ultimate tension value, shear strength and splitting strength of paste, in which the fly ash was partially replaced by limestone powder, was studied. Adiabatic temperature rise, setting time, shear strength, permeability, frost resistance and dry shrinkage of different substitution rate were investigated and the results were compared with traditional paste. The test results showed that the influence of limestone powder on workability, permeability and frost resistance performance of paste was slight, the setting time of paste were shortened, adiabatic temperature rise and mechanics performance of paste were decreased, dry shrinkage value was increased with limestone powder content increasing.

Properties of alkali activated slag–fly ash blends with limestone addition

In this article, the effects of raw materials’ composition on fresh behavior, reaction kinetics, mechanical properties and microstructure of alkali activated slag–fly ash–limestone blends are investigated. The results indicate that, with the increasing content of fly ash and limestone, the slump flow increases. The setting times are shortened when increasing the slag content, while both fly ash and limestone show a negligible influence. The reaction process is slightly accelerated by the presence of limestone due to the extra provided nucleation sites, but the reaction process is mainly governed by the slag. The slag content exhibits a dominant role on strength in this ternary system, while for a constant slag content, the compressive strength increases with the increasing limestone content up to 30%. The microstructure analysis shows that the gel characteristics are independent of the limestone powder content. The presence of limestone in initially high Ca and Al conditions does not lead to the formation of additional crystalline phases, which is different from Portland cement systems. Both physically and chemically bound water contents are slightly increased when limestone powder is incorporated.

Porosity of Self-compacting Concrete

The construction industry demands more durable concrete with high performance. Self-compacting concrete (SCC) is developing gradually to meet many aspects of construction technology, especially reinforced concrete. On the other hand, durability properties still need some enhancements particularly in term of microstructure properties. Furthermore, there is a lack of research on non-destructive testing of self-compacting concrete. Question arises: are the contexts on the strength of conventional normal concrete (NC) extendable on the strength of SCC? Laboratory tests were carried out at the BME, Department of Construction Materials and Technologies. Aim of the research was to determine the service life of SCC with respect to normal concrete. Constant and variable parameters were determined to the concrete mixes. Constant parameters were: type of cement CEM III-A 32.5 N-MS and grading curve of the aggregate. Variable parameters were: water-cement ratio, content of cement, content of limestone powder. The purpose of this study is to analyze the implementation of economical non-pozzolanic filler additive (limestone) into the concrete matrix of SCC. Normal and Self-compacting concrete mixes were prepared to reach a correlation between porosity indicators. Results indicated that SCC mixtures had more reliable rebound index and lower total porosity values than NC; whereas water absorption in SCC was found to show considerably higher values than referred NC mixes.

Effect of Limestone Powder on Acid Attack Characteristics of Cement Pastes

The acid resistance of cement pastes containing limestone powder with two different water-binder (w/b) ratios exposed to acetic (pH = 4) and sulfuric acid (pH = 2) solutions respectively were investigated in this paper. Limestone powder, fly ash and silica fume were also added to the cement paste mixture at different proportions. Static and flowing aqueous environments were set in this experiment. Strength and microstructure of the pastes after acid attack were investigated by using strength test, X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The experimental results show that the erosion degree depends not only on pH value of the solution and w/b ratio of the pastes, but also on the content of limestone powder. Acetic acid reacts with calcium hydroxide and carbonate thus dissolving the pastes, while sulfuric acid consumed calcium hydroxide, and generated gypsum and ettringite. The consumption of calcium hydroxide in the flowing solution group is higher than that in the static solution because the flowing sulfuric acid solution has negative effect upon the gypsum crystallization. Fly ash and silica fume are beneficial to limestone cement paste because of the less calcium hydroxide formation, which is among the hydrates vulnerable to acid erosion. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6231

Sulfate resistance of cement-reduced eco-friendly concretes

Two newly developed cement-reduced eco-friendly concretes with high limestone powder content and low water/powder ratio were tested for sulfate resistance. Mortar samples with a paste composition of eco- as well as conventional concretes were immersed in 30gl−1 Na2SO4 and saturated Ca(OH)2 reference solutions for 200days at 8°C. To evaluate the reaction mechanisms of progressing sulfate attack a combined approach of mechanical, mineralogical, and microstructural methods was applied.Gypsum and bassanite neo-formations related linearly to the expansion during sulfate exposure, except for one sample where ettringite co-precipitated. Thaumasite formation was not observed in spite of potentially favorable conditions. This is considered to be related to the evolution of the experimental solutions, kinetic effects, and the competing formation of CaCO3 polymorphs triggered by the usage of superplasticizer. Both eco-friendly mixes exhibited a better sulfate resistance than their corresponding reference samples and are therefore suggested to be applicable in low sulfate-loaded environments according to DINEN206-1. Eco-friendly concrete based on CEMIII/B performed superior against sulfate attack and is expected to withstand even severe sulfate exposure despite a much higher water/cement ratio than required by the standard.

The Influence and Suppression Effect of Limestone Powder on Concrete Shrinkage

In order to study the suppression effect of increasing concrete shrinkage induced by limestone powder, the aliphatic water reducer and polycarboxylate superplasticizer was used in experiments about effect of limestone powder content on concrete shrinkage. The results showed that the concrete shrinkage increased as the limestone powder content increasing. Comparing to the aliphatic water reducer, the polycarboxylate superplasticizer showed obviously effect on concrete shrinkage suppression. Besides, the polycarboxylate superplasticizer can reduce the sensitivity of concrete cracking. The polycarboxylate superplasticizer using in concrete can effectively reduce the emission amount and environmental pollution in the production process of artificial sand, simultaneously, this is helpful to improve the volume stability of concrete.

Influence of limestone powder on hydration properties of complex binders

In this paper, the influence of limestone powder on hydration properties of complex binder was studied by determining compressive strength of mortars and hydration heat of complex binders. Meanwhile, microcosmic analysis such as mercury intrusion porosimetry, scanning electron microscope and X-ray diffractometer, were also performed on those mortars. Because of the smaller particle size of limestone powder, it can form better gradation as fillers in the cementitious system. With the increasing limestone powder content, the proportion of small pores with diameter smaller than 50 or even 20 nm, which has little effect on the properties of the composite, increased and could make pores finer and improve the pore structure. At earlier period (28 days) limestone powder acts filling and accelerating effects by speeding up the hydration process of complex binder, but it will react with ordinary Portland cement to produce calcium monocarboaluminate hydrates, acting its activate effect at later period (180 days). Owing to its activate effect, it will improve early compressive strength, and also increase hydration exothermic rate while shorten its induction period.

Research on Static Compressive Experiment of Concrete Mixed with Limestone Power and Fly Ash

The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.

Study on the Influence of the Tailing Sand on the Performance of Pre-Mixed Mortar

Large applications of pre-mixed mortar and the dwindling natural sand resources make people feel anxiety about the sustainable development of pre-mixed mortar, therefore, it is imperative to find replacement of natural sand. In this paper, several kinds of local tailings are selected. First, the basic performances of tailing sand are analyzed, then, the effect of the tailing sand on the performances of pre-mixed mortar are tested. The tests show that the mortar performance meets the technical requirements absolutely when tailings are used as aggregate mix mortar. When tailings substitute the natural sand, the mortar has qualified consistency and hierarchical degrees, but the strength is slightly lower. The natural sands are added to the limestone with more content of limestone powder which enrich the aggregate gradation, decrease the porosity of the aggregate and increase the fluidity. Also, both the consistency and hierarchical degrees of the mortar are very good. The tailings can be partially or completely substituted for the natural sand to mix the mortar, therefore, the exploitable yield of the natural sand can be reduced. The tailings are very suitable for mixing mortar.